CN113815869A - Icing state aircraft angle of attack protection control method - Google Patents
Icing state aircraft angle of attack protection control method Download PDFInfo
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- CN113815869A CN113815869A CN202111123741.5A CN202111123741A CN113815869A CN 113815869 A CN113815869 A CN 113815869A CN 202111123741 A CN202111123741 A CN 202111123741A CN 113815869 A CN113815869 A CN 113815869A
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- 230000002159 abnormal effect Effects 0.000 claims description 8
- 230000007613 environmental effect Effects 0.000 claims description 4
- 230000003137 locomotive effect Effects 0.000 claims description 3
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- 238000010612 desalination reaction Methods 0.000 description 1
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64D—EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENTS OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT
- B64D15/00—De-icing or preventing icing on exterior surfaces of aircraft
- B64D15/20—Means for detecting icing or initiating de-icing
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64D—EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENTS OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT
- B64D45/00—Aircraft indicators or protectors not otherwise provided for
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64D—EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENTS OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT
- B64D47/00—Equipment not otherwise provided for
- B64D47/02—Arrangements or adaptations of signal or lighting devices
Abstract
The application provides an icing state aircraft angle of attack protection control method, which comprises the following steps: determining aircraft attack angle protection states under icing-free meteorological conditions and icing meteorological conditions; determining a judgment condition that the aircraft icing state attack angle protection function is allowed to be switched on; determining icing angle-of-attack protection logic for exiting to a normal ice-free state; expanding the limiting angle of attack and the warning angle of attack values under different icing states into a limiting angle of attack and warning angle of attack interpolation table under a normal ice-free state, and constructing an interpolation table which changes along with Mach number, lift-increasing configuration and angle of attack protection state as input information of an angle of attack protection function; after the interpolation table is expanded, the icing state follows the normal ice-free state attack angle protection control algorithm, the attack angle protection control function algorithms under icing and non-icing conditions are the same, only the input values are different, and for the pitching channel, when the attack angle is smaller than the alarm attack angle, overload control is adopted, and when the attack angle reaches the alarm attack angle, attack angle control is adopted, so that the maximum pull rod value correspondingly limits the attack angle.
Description
Technical Field
The application belongs to the technical field of flight control, and particularly relates to an icing state aircraft attack angle protection control method.
Background
When the airplane flies in icing weather, an ice layer is accumulated on the surface of the airplane body, so that the maximum lift force of the airplane is reduced, the resistance is increased, the aerodynamic performance is poor, and the maneuverability and the safety of the airplane are seriously influenced. Therefore, aircraft are usually designed with an angle of attack limiting protection function in natural icing weather to ensure safe flight of the aircraft in icing conditions.
The supersonic aircraft has high maneuverability, and can quickly fly away from an icing area if meeting icing weather, so the icing angle of attack protection function is not needed usually; however, large aircraft are difficult to fly away from an icing area quickly due to poor maneuverability, and therefore need a corresponding attack angle protection function. In the prior art, large airplanes in China are basically controlled mechanically or stably, and are difficult to realize a relatively complex automatic protection function of an angle of attack in an icing state, foreign large airplanes simply define the angle of attack in icing as two states of a normal ice-free environment and a wing icing environment according to the icing state of airplane wings, and do not consider the automatic switching logic of the angle of attack protection function and the automatic switching logic among the states under the conditions of empennage icing, airplane wing or empennage deicing prevention system faults.
Accordingly, a technical solution is desired to overcome or at least alleviate at least one of the above-mentioned drawbacks of the prior art.
Disclosure of Invention
The present application is directed to providing an icing condition aircraft angle of attack protection control method to solve or mitigate at least one problem of the background art.
The technical scheme of the application is as follows: an icing condition aircraft angle of attack protection control method, the method comprising:
determining an attack angle protection state under an icing-free meteorological condition and an icing meteorological condition, wherein the attack angle protection state comprises a normal state representing the icing-free meteorological condition, an icing state I representing the normal work of an anti-icing system under the icing meteorological condition and an icing state II representing the abnormal work of any anti-icing system under the icing meteorological condition;
acquiring signals of a high lift device state, an undercarriage state and an airplane wheel bearing state, and allowing an aircraft icing state attack angle protection function to be switched on when the high lift device is retracted and the undercarriage is retracted or the airplane wheel does not bear any load for more than a preset time;
when the icing detector detects that an icing signal exists on the airplane for a period of time, the airplane enters an icing state I by turning on the wing anti-icing switch or the empennage deicing switch;
in the first icing state, the icing detector detects that the aircraft flies in an icing area, and the aircraft wing anti-icing switch is turned on, the wing anti-icing system is in a normal state, the empennage de-icing switch is turned on, the empennage de-icing system is in a normal state, and the first icing state is maintained;
in the icing state I, the icing detector detects that the airplane flies in the icing area and exceeds a preset time, and meanwhile, any one of the condition that an airplane wing anti-icing switch is closed or a wing anti-icing system is abnormal or a tail wing de-icing switch is closed or a tail wing de-icing system is abnormal is met, and the airplane enters an icing state II;
in the icing state II, when the icing detector detects that the airplane leaves the icing area, the wing deicing switch is turned off, the empennage deicing switch is turned off, and the environmental temperature is higher than the preset temperature, the normal state is returned;
constructing a three-dimensional interpolation table which changes along with Mach number, a high-lift configuration and angle of attack protection state words representing a normal state, an icing state I and an icing state II, wherein data in the three-dimensional interpolation table is an aircraft limited angle of attack or an alarm angle of attack value;
and controlling the aircraft attack angle according to the data of the three-dimensional interpolation table and an attack angle protection control law.
Further, in the first icing state, when the icing detector detects that the airplane leaves the icing area, the wing anti-icing switch is turned off, the tail wing deicing switch is turned off, and the total ambient temperature is higher than the preset temperature, the protection function returns to the icing angle of attack and is allowed to be switched on.
Further, in the first icing state, when the icing detector detects that the aircraft leaves the icing area and is in the first icing state at the previous moment and the total ambient temperature is lower than the preset temperature, or the aircraft enters the first icing state for the first time and does not exceed the preset time, the aircraft is kept in the first icing state.
Further, the aircraft enters the icing state I from the normal state and is kept in the icing state I within a preset time.
Further, in the second icing state, when the icing detector detects that the aircraft leaves the icing area and is in the second icing state at the previous moment and the total ambient temperature is lower than the preset temperature, the aircraft is kept in the second icing state.
Further, in the icing state two, when the icing detector detects that the aircraft flies in the icing area, the aircraft wing anti-icing switch is turned on, the empennage de-icing switch is turned on, the wing anti-icing system is normal, the empennage de-icing system is normal, and the aircraft enters the icing state one.
Further, in the icing state I or the icing state II, after the bearing of the locomotive exceeds the preset time, the locomotive exits from the icing state attack angle protection and enters into the normal state attack angle protection;
further, the switching among the icing state I, the icing state II and the normal state has preset desalination time.
Further, the attack angle protection state word is transmitted to the CWS central warning system through the bus and displayed on the central panel.
According to the control method for protecting the aircraft attack angle under the icing weather, the automatic switching and protection functions of the aircraft attack angle under different icing weather conditions are realized according to signals whether different icing ice types on the aircraft airfoil surface and the airfoil surface ice prevention and removal system are in fault or not and signals related to icing provided by the environmental control system.
Drawings
In order to more clearly illustrate the technical solutions provided by the present application, the following briefly introduces the accompanying drawings. It is to be expressly understood that the drawings described below are only illustrative of some embodiments of the invention.
Fig. 1 is a schematic view of an icing condition aircraft angle of attack protection control method according to the present application.
FIG. 2 is a schematic diagram of condition 1 in the process of the present application.
FIG. 3 is a schematic diagram of condition 2 in the process of the present application.
FIG. 4 is a schematic diagram of condition 3 in the process of the present application.
FIG. 5 is a schematic view of condition 4 in the process of the present application.
FIG. 6 is a schematic view of condition 5 in the process of the present application.
FIG. 7 is a schematic view of Condition 6 in the process of the present application.
FIG. 8 is a schematic view of condition 7 in the process of the present application.
FIG. 9 is a schematic view of condition 8 in the process of the present application.
FIG. 10 is a schematic view of condition 9 in the process of the present application.
FIG. 11 is a schematic view of condition 10 in the process of the present application.
Detailed Description
In order to make the implementation objects, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be described in more detail below with reference to the drawings in the embodiments of the present application.
The method realizes the automatic switching and protection functions of the attack angle of the airplane under different icing weather conditions according to signals of whether different icing ice types and airfoil anti-icing and deicing systems on the airfoil surface of the airplane fail or not and icing related signals provided by an environmental control system.
The method provided by the application comprises the following steps:
1) and determining the aircraft attack angle protection state under the icing-free meteorological condition and the icing meteorological condition.
According to the airworthiness standard of the transportation type airplane, the requirements of the airplane performance and the operation quality under the atmospheric icing condition and the icing state are met, calculation analysis, an icing wind tunnel test and flight test with a model are carried out on the aerodynamic characteristics of the airplane under the icing condition, the working states of an anti-icing system with wings and an empennage of the airplane are combined, the ice types with similar influences are combined, the icing attack angle of the airplane is divided into different protection states, and attack angle protection is carried out. Each icing state corresponds to different alarm attack angles and limiting attack angle values;
through the work such as computational analysis and take model to try to fly, divide icing state angle of attack protection into two states:
icing state I: all icing states (including standby ice type, airway ice type in all flight states, and the like) of the ice preventing and removing system working normally have the following judgment logics: (the icing detector detects the icing of the aircraft) and [ (the wing anti-icing switch is working and the wing anti-icing system is normal) and (the empennage de-icing switch is working and the empennage de-icing system is normal) ];
and (2) icing state II: all icing states of any part preventing and removing ice system failure, which takes the most serious failure ice type into consideration for the attack angle protection of the airplane, and the judgment logic is as follows: (the icing detector detects an airplane icing signal) and [ (the wing anti-icing switch does not work) or (the wing anti-icing system is abnormal in state) or (the empennage de-icing switch does not work) or (the empennage de-icing system is abnormal in state) ].
In addition, the icing degree on the wings and the empennage of the airplane is small within 2 minutes just after the airplane is iced, and the safety of the airplane cannot be greatly influenced, so that the icing angle of attack is protected according to the icing state 1 within 2 minutes to ensure certain maneuvering performance of the airplane.
The attack angle protection under the icing-free meteorological condition belongs to a common process and is not described in detail.
2) And acquiring signals of the state of the high-lift device, the state of the undercarriage and the bearing state of the airplane wheels, and when the high-lift device is retracted and the undercarriage is retracted or the airplane wheels are not loaded for more than a preset time, the aircraft icing state attack angle protection function is allowed to be switched on.
The airplane takes off under the condition of icing weather, and ground deicing operation is required before taking off so as to ensure that the airplane takes off without ice. The aircraft is limited in aerodynamic influence of icing in the takeoff stage, so that the attack angle in the takeoff stage is protected in a normal ice-free state, and the attack angle protection function in the icing state is allowed to be switched on after takeoff is finished;
therefore, the specific logic for the takeoff phase is: (the wheel load signal is obtained to meet 2 minutes after the wheel load is lifted off the ground) or [ (the landing gear is controlled to retract through a landing gear handle) and (a hyperplasia device such as a flap is retracted) ], the icing protection is allowed to be switched on.
3) Icing condition angle of attack protection enable logic is determined.
Introducing signals of an icing detector, an icing switch of the wing and a tail deicing switch into the received bus signals, and after the icing detector icing signals on the airplane are detected for a period of time continuously after icing angle protection is allowed, or (considering the priority of a pilot), manually turning on the icing switch of the wing or the tail deicing switch, and starting the icing state angle of attack protection function;
4) and determining that the icing angle-of-attack protection exits to normal ice-free state angle-of-attack protection logic.
And after the airplane starts icing protection, if the airplane lands for more than a certain time, the airplane exits from normal ice-free state attack angle protection.
In addition, when the aircraft leaves the icing meteorological environment and the icing state attack angle protection function is not met (namely when any condition in the step 3 is not met), when the total temperature of the environment is high enough to ensure that the airfoil surface of the aircraft has no residual ice layer, the attack angle protection is quit to the normal ice-free state attack angle protection;
5) step 1-4 is the attack angle protection function logic under the natural icing meteorological condition, and the logic is used as an independent module to be added into a flight control law;
6) expanding the limiting angle of attack and the warning angle of attack values in different icing states provided in the step (1) into a limiting angle of attack and warning angle of attack interpolation table in a normal non-icing state, and constructing an interpolation table which changes along with Mach number, lift-increasing configuration and angle of attack protection state as input information of an angle of attack protection function;
after the interpolation table is expanded, the icing state can directly follow the attack angle protection control algorithm in the normal ice-free state, the attack angle protection control function algorithms under the icing condition and the non-icing condition are the same, only the input values (the limiting attack angle and the alarm attack angle value) are different, and the protection algorithm is not repeated herein. For the pitch channel, when the attack angle is smaller than the alarm attack angle, overload control is adopted, and when the attack angle reaches the alarm attack angle, attack angle control is adopted, so that the maximum pull rod value correspondingly limits the attack angle;
in the preferred embodiment of the present application, in order to facilitate the pilot to know the current protection state of the angle of attack, the protection state of the angle of attack is introduced into the central warning system CWS through a bus signal and displayed on the central panel.
The central warning system CWS can display the icing state 1 or the icing state 2 according to the current attack angle protection state, so that the pilot can conveniently learn the current attack angle protection state.
The attack angle protection control method provided by the invention can realize aircraft attack angle protection in an icing state, can directly use an attack angle protection algorithm in a normal ice-free state, and does not need to change a control law framework; in addition, the application of the invention does not need to modify any system component of the airplane, and can be directly realized in flight control software, thereby greatly reducing the modification cost, ensuring the use accuracy of the attack angle protection function in normal and natural icing states, and improving the safety of the airplane.
The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present application should be covered within the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.
Claims (9)
1. An icing condition aircraft angle of attack protection control method, characterized in that the method comprises:
dividing the aircraft attack angle protection state into a normal state representing the non-icing meteorological condition, an icing state I representing the normal work of an anti-icing system under the icing meteorological condition and an icing state II representing the abnormal work of any anti-icing system under the icing meteorological condition;
acquiring signals of a high lift device state, an undercarriage state and an airplane wheel bearing state, and allowing an aircraft icing state attack angle protection function to be switched on when the high lift device is retracted and the undercarriage is retracted or the airplane wheel does not bear any load for more than a preset time;
when the icing detector detects that an icing signal exists on the airplane for a period of time, the airplane enters an icing state I by turning on the wing anti-icing switch or the empennage deicing switch;
in the first icing state, the icing detector detects that the aircraft flies in an icing area, and the aircraft wing anti-icing switch is turned on, the wing anti-icing system is in a normal state, the empennage de-icing switch is turned on, the empennage de-icing system is in a normal state, and the first icing state is maintained;
in the icing state I, the icing detector detects that the airplane flies in the icing area and exceeds a preset time, and meanwhile, any one of the condition that an airplane wing anti-icing switch is closed or a wing anti-icing system is abnormal or a tail wing de-icing switch is closed or a tail wing de-icing system is abnormal is met, and the airplane enters an icing state II;
in the icing state II, when the icing detector detects that the airplane leaves the icing area, the wing deicing switch is turned off, the empennage deicing switch is turned off, and the environmental temperature is higher than the preset temperature, the normal state is returned;
constructing a three-dimensional interpolation table which changes along with Mach number, a high-lift configuration and angle of attack protection state words representing a normal state, an icing state I and an icing state II, wherein data in the three-dimensional interpolation table is an aircraft limited angle of attack or an alarm angle of attack value;
and controlling the aircraft attack angle according to the data of the three-dimensional interpolation table and an attack angle protection control law.
2. The icing condition angle of attack protection control method according to claim 1, wherein in the icing condition one, when the icing detector detects that the aircraft leaves the icing area, the wing anti-icing switch is turned off, the tail wing de-icing switch is turned off, and the total ambient temperature is greater than a predetermined temperature, the control method returns to the icing angle of attack protection function and allows the aircraft to be turned on.
3. The icing condition angle of attack protection control method according to claim 1, wherein in icing condition one, when the icing detector detects that the aircraft has left the icing area and was in icing condition one at the previous time and the total ambient temperature is less than the predetermined temperature, or the aircraft first enters icing condition one and does not exceed the predetermined time, the aircraft is kept in icing condition one.
4. The icing condition angle of attack protection control method of claim 1, wherein the aircraft is maintained in the icing condition one when entering the icing condition from the normal condition one and not more than a predetermined time.
5. The icing condition angle of attack protection control method according to claim 1, wherein in the icing condition two, when the icing detector detects that the aircraft leaves the icing area and is in the icing condition two at the previous moment and the total ambient temperature is less than the predetermined temperature, the aircraft is kept in the icing condition two.
6. The icing condition angle of attack protection control method according to claim 1, wherein in the icing condition two, when the icing detector detects that the aircraft is flying in the icing area, and the aircraft wing anti-icing switch is turned on and the tail wing anti-icing switch is turned on and the wing anti-icing system is normal and the tail wing anti-icing system is normal, the aircraft enters the icing condition one.
7. The icing condition angle of attack protection control method according to claim 1, wherein in the icing condition one or the icing condition two, after the loading of the locomotive exceeds a predetermined time, the icing condition angle of attack protection is exited, and the normal condition angle of attack protection is entered.
8. The icing condition angle of attack protection control method according to claim 1, wherein switching between the icing condition one, the icing condition two, and the normal condition has a predetermined fade time.
9. The icing condition angle of attack protection control method of claim 1, wherein the angle of attack protection status word is transmitted to the CWS central warning system through a bus and displayed on a central panel.
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| CN202111123741.5A CN113815869B (en) | 2021-09-24 | 2021-09-24 | Icing aircraft attack angle protection control method |
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| CN202111123741.5A CN113815869B (en) | 2021-09-24 | 2021-09-24 | Icing aircraft attack angle protection control method |
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2867153A1 (en) * | 2004-03-03 | 2005-09-09 | Goodrich Corp | Hoar frost removal process for airplane wing, involves heating de-icing zones at rear curved part of structural unit, by utilizing electro-thermal device, to supply hot surface water to accumulated molten hoar frost |
| CN105416593A (en) * | 2015-12-11 | 2016-03-23 | 中国航空工业集团公司西安飞机设计研究所 | Aircraft deicing system |
| CN112373697A (en) * | 2020-10-30 | 2021-02-19 | 哈尔滨飞机工业集团有限责任公司 | Aircraft icing stall warning system and method |
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2021
- 2021-09-24 CN CN202111123741.5A patent/CN113815869B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2867153A1 (en) * | 2004-03-03 | 2005-09-09 | Goodrich Corp | Hoar frost removal process for airplane wing, involves heating de-icing zones at rear curved part of structural unit, by utilizing electro-thermal device, to supply hot surface water to accumulated molten hoar frost |
| CN105416593A (en) * | 2015-12-11 | 2016-03-23 | 中国航空工业集团公司西安飞机设计研究所 | Aircraft deicing system |
| CN112373697A (en) * | 2020-10-30 | 2021-02-19 | 哈尔滨飞机工业集团有限责任公司 | Aircraft icing stall warning system and method |
Non-Patent Citations (1)
| Title |
|---|
| 王小龙;徐浩军;薛源;朱和铨;裴彬彬;: "俯仰姿态保持模式下飞机结冰边界保护方法", 航空动力学报, no. 09, pages 44 - 51 * |
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